The classic worry for central bankers is a wage-price spiral, where higher wages beget higher prices, pushing up inflation. The conundrum in the U.K. is that prices are rising while wages are stagnating.

Wednesday's labor-market data showed that regular pay excluding bonuses rose just 0.7% in March-May versus the same period a year earlier. That was in line with forecasts, but the lowest annual growth rate since records began in...